The present invention relates to an improvement in the manner in which a tonneau cover is attached to a pickup truck box. More specifically, a method of attachment which allows for the adjustment of the tonneau cover in order to provide the user with a means by which the tension placed upon the tonneau cover can be varied to provide a tight seal in varying conditions and as the cover ages or stretches.
In the past, tonneau covers have been used to cover box openings of pickup trucks to protect the contents from wind, rain and snow, or simply for cosmetic reasons. The types of tonneau covers and methods of fastening the covers have varied greatly over the years. In recent years, one type of cover that has been commonly used is a tonneau cover that attaches at one end, typically the front end nearest the cab of the vehicle, in a permanent fashion. The sides and tailgate area are fastened to box of the pickup when closed. In the open position, the cover may be rolled forward toward the cab of the pickup and the attached end of the tonneau cover.
The problem with this type of arrangement is that tonneau covers may stretch over time. This can be greatly affected by the weather and use or stress placed upon the tarp. As the tarp sags, it may begin to look aesthetically poor and cause problems such as puddling of water. This can be especially dangerous when the puddles freeze, resulting in chunks or sheets of ice that fly off during travel and create hazards for other drivers on the road. A second problem caused by sagging tonneau covers is wind flap. This occurs during travel of the vehicle when the tonneau cover flaps in the wind causing noise and creating undue wear and greater stretching of the cover.
In order to deal with this problem, tonneau cover makers have developed ways of adjusting the position of the front portion of tonneau cover. Typically, the front portion may be bolted on rail or brace system with clamps and thus, the bolts may be loosened and moved on the rail to adjust the position of the front portion of the cover, in turn affecting the tension of the cover when in the attached position. This type of system requires the use of tools and trial and error to get the correct tension of the tonneau cover. It may also be very difficult to adjust each side accurately and evenly with the other. Due to the difficulty in making these adjustments many tonneau cover owners ignore the problem of improperly adjusting the cover after installation and thus, creating undue stress and wear on the cover as well as posing a potentially dangerous condition for others on the road.
From this discussion it can be seen that it would be desirable to create a means of easily adjusting the tension and position of tonneau covers used on pickups today. It can also be seen that it would be advantageous to make this adjustment as easy as possible to make and to insure that users keep their covers in taught arrangement to prevent the problems listed above and to keep the tonneau cover as aesthetically pleasing as possible.